Previous studies of acute necrotizing ulcerative gingivitis (ANUG) have associated disease activity with leukocyte dysfunction (PMN and lymphocyte). More recently, ANUG and ANUG-like infections have been reported in patients infected with the human immunodeficiency virus (HIV). The periodontal clinical features of HIV infection can span from asymptomatic to opportunistic infections to neoplasia. Presently, the most accurate predictor of the severity of immune dysfunction in HIV infection appears to be the absolute number of circulating CD4 T lymphocytes. The specific aims of this study are: 1. to characterize the periodontal microflora from HIV-seronegative and seropositive ANUG patients 2. to assess lymphocyte subpopulations and their function in this same group 3. to assess WBC and differential profiles in this same group This study in patients with ANUG or ANUG-like lesions will investigate the HIV-serostatus, periodontal microflora, WBC counts and differentials, and lymphocyte subpopulations (CD4/CD8) and their function. The periodontal microflora will be characterized by cultural and microscopic methods. The lymphocyte function tests will measure lymphocyte activation and interleukin-2 production in T cells isolated from peripheral blood. The aforementioned parameters will also be examined in the following groups: 1. HIV-sero- negative with periodontal health; 2. HIV serropositive with periodontal health; 3. HIV-seropositive, moderate-severe periodontitis; 4. HIV(high risk) seronegative with periodontal health. ANUG or a severe painful gingivitis may be a frequent early clinical sign of HIV infection and may serve as a predictor for future development of AIDS. Further elucidation of clinical or laboratory markers of HIV infection and of preactors for the development of AIDS will benefit the patient, public health officials, and care providers in timing of therapy, prevention of HIV transmission, and design of clinical trials.